Discharge door operating mechanism for rubber mixers and the like



7 June 2, 1964 P. J. BARAN DISCHARGE DOOR OPERATING MECHANISM FOR RUBBERMIXERS AND THE LIKE '2 Sheets-Sheet 1 Filed July 20, 1962 INVENTOR pever J. 5 1mm f %EYS June 2, 1964 P. J. BARAN 3,135,440

DISCHARGE DOOR OPERATING MECHANISM FOR RUBBER MIXERS AND THE LIKE 2Sheets-Sheet 2 Filed July 20, 1962 INVENTOR Pe+er J. Baron ATTORNEYS 1United States Patent 3,135,440 DISCHARGE DOOR OPERATING MECHANISM FORRUBBER MIXERS AND THE LIKE Peter J. Baran, Seymour, Conn., assignor toFarrel- Birmingham Company, Incorporated, Ansonia, Conn., a corporationof Connecticut Filed July 20, 1962, Ser. No. 211,349 Claims. (Cl.222-504) This invention relates to rubber mixers and like devices andmore particularly relates to a door and actuating mechanism therefor toallow discharge of material from a mixing chamber.

Mixers of a type to which this invention pertains generally comprise achamber into which material to be mixed is placed, with bladed rotorsrotatably mounted within the chamber to mix and knead the material. Themixing chamber is usually provided with a lower discharge openingthrough which material is discharged after it has been mixed, and thisopening is closed by a discharge door movably mounted on the frame ofthe mixing machine so that it may be moved to and from a closedposition.

In most instances the material to be mixed in the mixing chamber isworked under considerable pressure and often consists of powders orfinely divided materials which may have a tendency to escape from thechamber if there is opportunity. It is therefore, quite important thatthe discharge door positively fit closely and tightly against the edgesof the discharge opening so as to prevent the escape of materials fromthe chamber. Mixing devices and discharge doors therefor of a type towhich this invention pertains are disclosed in US. Patents 2,939,616 and2,962,186 assigned to the same assignee as the present invention.

It is an object of this invention to provide a new and improved mixingdevice having a discharge closure door and mechanism therefor whichinsures that the closure door is positively and firmly seated in thedoor opening to prevent any escape of materials therefrom.

It is another object of this invention to provide a new and improveddischarge door operating mechanism for a mixer of the type described.

It is a further object of this invention to provide a new and improveddischarge door operating mechanism for a mixer of the type describedwherein the operating mech-- anism exerts a high seating force on thedischarge door as it closes to positively seal the discharge opening.

The features of the invention which are believed to be novel are definedwith particularity in the claims appended to and forming part of thisspecification. However, the invention, both as to its organization andoperation, together with further objects and advantages thereof, maybest be appreciated by reference to the following description taken inconjunction with the drawings wherein:

FIG. 1 is anelevation of a mixing device embodying the invention, and

FIG. 2 is a view seen along a line 2-2' of FIG. 1.

The drawings illustrate a mixer 8 of the Banbury-type having walls 9defining a mixing chamber 10 in the form of overlapped cylinders inwhich a pair of shafts with mixing blades thereon, not shown, arerotatably mounted in shaft supports 11 and 12 on the mixer frame. Belowand between the mixing shaft mountings, a longitudinally extendingdischarge opening 13 is defined by parallel edge portions 14 and 15 ofwall 9 extending into inwardly inclined discharge-opening closuresurfaces 16 and 17, respectively. The discharge opening 13 is arrangedto be closed by a discharge door which comprises a closure door member18 of generally inverted V-shape, in section. Door member 18 hasinclined surfaces 18a and 18b 3,135,440 Patented June 2 1964 thereonarranged to mate with closure surfaces 16 and 17 and to allow door 18 tobe tightly fitted within opening 13 as hereinafter explained. Thedischarge door further comprises door support members 19 which aremounted on a shaft 20 which is journaled in the frame of the machine sothat door member 18 is arranged to be rotated between open and closedpositions.

It may be noted in FIG. 1 that the door member 18 is carried on two doorsupport members 19, however, the number of door supporting members,together with the operating mechanism therefor is optional. The doormember 18 may be mounted and supported on door support members 19 in anysuitable manner, however, door member 18 is preferably mounted on doorsupport members 19 in accordance with the teaching of Patent 2,939,-616.

Shaft 20 with door support member 19 thereon is rotatable between aclosed position as shown in solid line and open position as shown inbroken line (FIG. 2). The mixing chamber 10 is supported on a base plate22 provided by a base member 23 into which the mixed substance isdischarged when the door member 18 is moved to an open position.

In accordance with the invention a new and improved door operatingmechanism is provided which, in the preferred form illustrated,comprises first lever members 24 pivotally connected about a pin orshaft 25 carried between spaced jaws 26 of each of support members 19.Second lever members 27 are mounted at one end thereof about a pin orshaft 28 journaled in adjustable bearing mounts 29 which are carried onsupport member 30 provided by the base member 23. The bearing mounts 29are secured to the support member 30 by means of bolts 31 extendingtherethrough and threadably received in support member 30. The bolts 31are received in a slot 32 defined in each bearing mount 29, to allowpositional adjustment of the bearing mounts 29 on support member 30 forreasons hereinafter explained. A stopping plate 33 is secured to supportmember 30 by means of bolts 34 and adjusting bolts 35 extendtherethrough to adjust the position ofbearing mounts on support member30.

The other ends of both levers 24 and 27 are pivotally mounted about apivot pin or shaft 36 which is also pivotally connected to a forcetransmitting means which, as illustrated, comprises fluid pressureactuated cylinders 37 each having a reciprocating piston 38 therein on apiston shaft 39 which is connected to shaft 36 by means of yoke 40..Cylinders 37 are arranged for bidirectional operation to movedoor-support member 19 to a closed position as shown in full line inFIG. 2 or to an open position as shown in broken line, and are pivotallymounted on pins 41 at one end thereof carried by spaced brackets 42(only one shown) secured to base member 23. Cylinders 37 are of the typewhich are actuated by introduction of fluid into the cylinder on eitherside of piston 38.

As will be noted in FIG. 2 lever member 24 has an arm or finger 43extending therefrom providing a surface 43a. Lever member 27 provides aportion 44 having a surface 44a adjacent but spaced from surface 43a.The purpose of surfaces 43a and 44a is hereinafter explained.

Considering now the operation of the mechanism disclosed, if a fluidunder pressure is introduced into duct or fitting 45 of cylinder 37 toexert a force on piston 38, piston shaft 39 through yoke 40 carriedthereon transmits a force to shaft 36 moving shaft 36 towards theposition shown in broken line. This movement of shaft 36 rotates doorsupport member 19 and moves door 18 from opening 13, allowing materialwhich has been mixed in mixing chamber 10 to discharge through opening13 into base member 23. As fluid continues to be introduced throughfitting 45 into cylinder 37 and moves piston 38 so that piston shaft 39moves outwardly of cylinder 37 the door 18 and door support member 19will rotate to the full open position shown in broken line. When it isdesired to close discharge opening 13 fluid may be introduced intocylinder 37 through fitting 46 and exert a force on piston 38 causingpiston 38 to move towards a left hand position (as shown in FIG. 2),retracting piston shaft 39 into cylinder 37.

This causes yoke 40 to pull shaft 36 towards the position shown in fullline in FIG. 2 and rotate support members 19 clockwise, moving door 18towards a closed position.

In accordance with the invention, the levers 24 and 27 are so selectedand arranged that the door 18 reaches a closed position with surfaces18a and 18b thereof contacting closure surfaces 16 and 17, respectively,without the axis 47 of shaft 36 becoming aligned with the axes 48 and 49of shafts 25 and 28, respectively. Then, as piston 38 continues to pullshaft 36 towards the full line position shown in FIG. 2 the doorsurfaces 18a and 18b are forceably wedged against the inclined closuresurfaces 16 and 17 and upwardly into opening 13 to provide a tight andpositive fit of door 18 into opening 13 and thus seal opening 13 againstpossible escape of material from mixing chamber 10. It may be seen thatthe lever members 24 and 27 are not permitted to reach their totaleffective length (the sum of the lengths of lever members 24 and 27) inclosing door member 18, but in attempting to reach their total effectivelength under the force exerted on shaft 36 by piston shaft 39, wedgedoor surfaces 18a and 18b along closure surfaces 16 and 17.

With door 18 tightly wedged into and sealing opening 13, if it shouldnow be desired to allow discharge of material from mixing chamber 10,fluid may be introduced into fitting 45 to exert a force on shaft 36through piston 38 and yoke 40 to positively and rapidly move doorsupport members 19 and levers 24 and 27 to the broken line positionillustrated in FIG. 2. Piston 38 exerts a high force on support member19 through lever 24 which quickly dislodges the door 18 from its wedgedposition between surfaces 16 and 17 and permits door 18 to quickly openand allow discharge of material from mixing chamber 10.

While the cylinder 37 has been illustrated as a preferred forcetransmitting means, it is apparent that other force transmitting ormechanism operating means could be utilized as for example, a rotarycylinder adapted to rotate shaft 23 in a manner illustrated in Patent2,939,- 616.

As previously mentioned, the bearing mounts 29 are made adjustable onsupport member 30 so that the desired adjustment of the axes 47, 48 and49 on shafts 36, 25 and 28, respectively, can be initially obtained toplace door 18 in a tightly closed and locked position, and also so thatadjustments can be made to obtain this condition from time to time asthe various parts of the operating mechanism may wear slightly and alterthe desired alignment.

The surfaces 43a and 44a provide gaging surfaces to aid in properadjustment of the lever members 24 and 27. It is important that inmaking such adjustment, a clearance be left between surfaces 43a and 44aso that as the surfaces 16, 17, 18a and 18b wear, the lever mem' bers 24and 27 may extend their effective length (the distance between axes 48and 49 when door 18 is in a closed position) to insure that door member18 may be tightly inserted into opening 13. Surfaces 43a and 44a mayfurther act as a stopping means, upon wear of surfaces 16, 17, 18a and18b, to insure that upon closing of opening 13 by door member 18 theaxis 47 of shaft 36 4 will not move through a plane defined by axes 48and 49 and therefore tend to withdraw door 18 from opening 13. In FIG.2, it may be noted that axis 47 about which lever members 24 and 27 arecommonly pivotal lies without the plane defined by axes 48 and 49 in theclosed position, which is identified by numeral 50, and therefore aspiston shaft 39 draws shaft 36 to the left (as seen in FIG. 2), theeffective distance between axes 48 and 49 increases, wedging doorsurfaces 18a and 18b inwardly toward chamber 10 along surfaces 16 and17.

While the invention for purposes of disclosure has been illustrated in apreferred form thereof, modifications to the disclosed embodiment of theinvention and other embodiments thereof may occur to those skilled inthe art which do not depart from the spirit and scope of the invention.Therefore, it is intended in the appended claims to cover allmodifications of the disclosed embodiment of the invention, togetherwith other embodiments thereof which do not depart from the spirit andscope of the invention. e

What is claimed is:

1. A door operating mechanism for a mixing device comprising a framemember defining a mixing chamber having walls defining a lower dischargeopening therein; a door arranged to close said opening, said door beingpivotally mounted on said frame for movement toward and from saidopening, said operating mechanism comprising: a first lever pivotallyconnected at one end thereof about a first axis to said door; a secondlever pivotally mounted adjacent one end thereof about a second axisparallel to and spaced from said first axis; the other ends of saidlever members being pivotally connected about a third axis; means forexerting a force on one of said levers to produce rotation thereof aboutits respective axis and thereby cause rotation of said door member aboutits pivotal axis; said levers being of such length that the distancebetween said first and second axes is less than the sum of the lengthsof said levers when said door closes said opening, whereby upon urgingof said lever members toward a position in which said first, second andthird axes reside in a common plane said door is urged into saidopening.

2. The mechanism of claim 1 wherein cooperative means are provided onsaid levers to prevent said levers from rotating about said first andsecond axes to decrease the distance between said axis when said doormember is moved into a closed position.

3. The mechanism of claim 1 wherein said second axis is provided by ashaft mounted in a bearing mount and said mount is adjustable todetermine the distance between said first and said second axes when saiddoor is in a closed position.

4. The mechanism of claim 3 wherein said levers provide portions havingfacing surfaces when said door is in a closed position, said surfacesproviding gaging surfaces to aid in determining the desired position ofsaid bearing mount.

5. The arrangement of claim 3 wherein said other ends of said levers areconnected to a shaft and said means for exerting a force acts on saidshaft.

References Cited in the file of this patent UNITED STATES PATENTS1,542,341 Deckert June 16, 1925 3,052,384 Clark Sept. 4, 1962 FOREIGNPATENTS 515,433 Belgium Nov. 29, 1952 583,170 Italy Oct. 7, 1958 738,316Germany Aug. 11, 1943

1. A DOOR OPERATING MECHANISM FOR A MIXING DEVICE COMPRISING A FRAMEMEMBER DEFINING A MIXING CHAMBER HAVING WALLS DEFINING A LOWER DISCHARGEOPENING THEREIN; A DOOR ARRANGED TO CLOSE SAID OPENING, SAID DOOR BEINGPIVOTALLY MOUNTED ON SAID FRAME FOR MOVEMENT TOWARD AND FROM SAIDOPENING, SAID OPERATING MECHANISM COMPRISING: A FIRST LEVER PIVOTALLYCONNECTED AT ONE END THEREOF ABOUT A FIRST AXIS TO SAID DOOR; A SECONDLEVER PIVOTALLY MOUNTED ADJACENT ONE END THEREOF ABOUT A SECOND AXISPARALLEL TO AND SPACED FROM SAID FIRST AXIS; THE OTHER ENDS OF SAIDLEVER MEMBERS BEING PIVOTALLY CONNECTED ABOUT A THIRD AXIS; MEANS FOREXERTING A FORCE ON ONE OF SAID LEVERS TO PRODUCE ROTATION THEREOF ABOUTITS RESPECTIVE AXIS AND THEREBY CAUSE ROTATION OF SAID DOOR MEMBER ABOUTIS PIVOTAL AXIS; SAID LEVERS BEING OF SUCH LENGTH THAT THE DISTANCEBETWEEN SAID FIRST AND SECOND AXES IS LESS THAN THE SUM OF THE LENGTHSOF SAID LEVERS WHEN SAID DOOR CLOSES SAID OPENING, WHEREBY UPON URGINGOF SAID LEVER MEMBERS TOWARD A POSITION IN WHICH SAID FIRST, SECOND ANDTHIRD AXES RESIDE IN A COMMON PLANE SAID DOOR IS URGED INTO SAIDOPENING.